Dextro-naloxone counteracts amphetamine-induced hyperactivity.
The locomotor stimulating effect of d-amphetamine in mice was counteracted by the administration of l-naloxone [(-)-naloxone], a known opiate receptor antagonist. Mice injected with amphetamine reached a peak locomotor activity within 30 min. When treated simultaneously with amphetamine and l-naloxone, these subjects showed low motility. Furthermore, when mice were treated not with l-naloxone but with its mirror image, d-naloxone [(+)-naloxone], a compound that by itself does not antagonize opiates and does not affect spontaneous motility, they showed no amphetamine-induced hyperactivity. The finding that an enantiomer of naloxone, with no opiate antagonist activity, is able to block the excitatory action of amphetamine, suggests the existence of a hitherto unknown mechanism of counteracting some of the effects of stimulants and euphoriants like amphetamine and cocaine.
Chatterjie
N
N
New York State Institute for Basic Research in Developmental Disabilities, Staten Island 10314, USA.
Sechzer
J A
JA
Lieberman
K W
KW
Alexander
G J
GJ
D000661:Amphetamine / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D015259:Dopamine Agents / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D008297:Male; D051379:Mice; D009020:Morphine / Q000494:pharmacology; D009043:Motor Activity / Q000187:drug effects*; D009270:Naloxone / Q000494:pharmacology*; D009292:Narcotic Antagonists / Q000494:pharmacology*; D009294:Narcotics / Q000494:pharmacology; D013237:Stereoisomerism
D015259:Dopamine Agents; D009292:Narcotic Antagonists; D009294:Narcotics; D009270:Naloxone; D009020:Morphine; D000661:Amphetamine